Flexible drill string and operating apparatus therefor



S. O. BRESIN ET AL Aug. 12, 1969 FLEXIBLE DRILL STRING AND OPERATINGAPPARATUS THEREFOR Filed July 19, 1965 2 Sheets-Sheet l INVENTOfiSkeZdon O: Bresin Donald E. Ross 96 1 2030? 58. $04:

AGENT Aug. 12, 1969 s. o. BRESIN ET AL 3,460,563

FLEXIBLE DRILL STRING AND OPERATING' APPARATUS THEREFOR Filed July 19,1965 2 Sheets-Sheet 2 Fig. 3

IN VENTORS S'keldon O. Bresz'n Donald E. Ross AGENT United States PatentM 3,460,563 FLEXIBLE DRILL STRING AND OPERATING APPARATUS THEREFORSheldon O. Bresin and Donald E. Ross, Huntsville, Ala.,

assignors to Northrop Corporation, Beverly Hills,

Calif., a corporation of California Filed July 19, 1965, Ser. No.473,127 Int. Cl. B65h 75/46 US. Cl. ISL-355.26 Claims ABSTRACT OF THEDISCLOSURE A drilling assembly, adapted to operate in atmospheric ornonatmospheric environments, including a flexible member Wound on a reelmember. The cylindrical portion of the reel member having a spiralgroove formed therein, the flexible member in its assembled relation onthe reel being received in the groove. The flexible member has high .andlow pressure passageway therein and the concentric relation lendingrigidity and stiffness to the flexible member when inflated. Theassembly also includes a torque sensing unit functioning to arresttwisting action originating in one portion of the flexible member frombeing transmitted to other portions of the flexible member.

The present invention pertains to drilling facilities adapted to effectdrilling operations and obtain core samples and more particularly todrilling equipment facilitating a drilling operation and the securing ofcore samples on the linear surface.

Briefly the present equipment comprises a flexible hose (drill string)wound in a continuous spiral groove formed in the outer cylindricalsurface of a drum. The hose is of braided wire construction which inturn is coated with a flexible material, the material being non-perviouswith respect to pressurized gas used in the subject drilling equipment.The coating material has convolutions formed in the outer surfacethereof which mate with complimentary convolutions formed in the grooveprovided in the drum. The internal portion of the hose includeslongitudinally extending passageways adapted to carry high and lowpressure gas. One end of the hose is secured to sources of high and lowpressure gas and rotates with the drum, the other end carries a gasactuated drilling tool. Constructed in the above manner it will beapparent that the hose is unwound from the drum, in response to a rotarymovement of the latter, and will function as a segmented drill stringhaving a degree of stiffness adapted to transmit a force sufiicientlygreat to effect a drilling operation.

Also it will be apparent that the drilling equipment as disclosed willeliminate the use of conventional drill strings (segmented casings) and,therefore, will eliminate the arduous task of positioning and connectingthe same, thus enabling an astronaut to conserve his energy for forimportant activities.

Accordingly it is an object of the present invention to disclosedrilling equipment constructed and functioning in a manner eliminatingthe need of utilizing for conventional segmented drill strings.

Another object is to provide drilling equipment which is self-containedrequiring very little effort on the part of an operator of theequipment.

Another object is to provide drilling equipment including a hose whichis alternately flexible and rigid when the equipment is deactivated andactivated, respectively.

3,460,563 Patented Aug. 12, 1969 Another object is to provide drilling;equipment which is simple in design, economical to manufacture,efficient in operation and which may be easily adapted to any purposefor which it is intended.

Although the characteristic features of the present in vention areparticularly pointed out in the appended claims, the invention itself,also the manner in which it may be carried out, will be betterunderstood by re ferring to the following description taken inconnection with the accompanying drawings forming a part of thisapplication and in which:

FIGURE 1 is a perspective view of the drilling equipment as disclosedherein shown in its operating position associated with a space vehicle.

FIGURE 2 is an enlarged perspective view of the drilling equipment ofFIGURE 1.

FIGURE 3 is a fragmentary sectional view of the drilling equipment ofFIGURE 2 taken substantially on the line 3-3 of FIGURE 2.

FIGURE 4 is a cross-sectional view of the drill string comprising acomponent of the drilling: equipment shown inFIGURE2.

Referring to the drawings, FIGURE 1 shows drilling equipment 11 asdisclosed herein as being utilized in a space environment, the equipmentbeing attached to and used with a space or landing vehicle (not shown).Although the subject equipment is shown and described as being utilizedin a space environment it should be understood that the equipment hasother applications and may be utilized on earth to effect a drillingoperation or for obtaining core samples.

During flight the equipment 11 is stored in a compartment (not shown)provided in the aforementioned landing vehicle, the compartment in turnis closed by a closure member 12. The member 12 functions during flightsubstantially as closing of the door housing the landing gear on anaircraft. The equipment 11 is moved between its stored position (notshown) and its operating position (FIGURE 1) on a support arm 14. Theequipment 11 is rotatably mounted adjacent the midportion of the arm 14while the right end of the arm (FIGURE 1) is pivotally attached to fixedstructure of the landing vehicle.

The drilling equipment 11 includes a drum, drill strings, sealedcompartment or chamber and an electric motor 16, 17, 18 and 19,respectively, as best seen in FIGURE 2.

The drum 16 is constructed of light but strong material, it is of hollowconstruction constituting substantially a shell 21 pivotally supportedon a shaft 22 by means of spider-like legs 23. The shaft 22 is in turnfixedly supported by the arm 14 at approximately the mid-point of thelatter. A continuous spirally formed groove 24 is provided in the outersurface of the shell 21, the groove having a plurality of spaceddepressions 26 defining convolutions formed therein adapted to mate withprojecting (convolutions) formed in the outer surface of the drillstring 17.

The drill string 17 constitutes a continuous flexible hose or conduithaving high and low pressure passageway 28 and 29, respectively,provided therein. The drill string 17 constitutes an outer conduit orhose 27 and an inner conduit 30. The inner surface of the conduit 27 isconstructed of braided wire while its outer surface is coated withTeflon or similar material which is nonpervious to pressurized gasutilized in the equipment 11. The conduit 30, defining the passageway28, is fabricated of rubber or similar material, is circular incross-section and extends throughout the length of the conduit 27 andhas a plurality of radially extending finn-like members 31 on its outersurface thereof. The members 31 function to maintain a concentricrelation between the conduits 27 and and also to define theaforementioned passageways 29. The passageway 28 functions to carry highpressure gas from a compressor located in the chamber 18 to an airactuated drilling tool (not shown) located at the lower end of the drillstring 17 while the passageways 29 function to return low pressure gasfrom the drilling tool to the chamber 18. The conduit 27 is covered witha flexible material, non-pervious to pressurized gas used in theequipment 11, for example, Teflon or other similar materials.Convolutions 26 (previously referred to) constitute spaced projectionsadapted to mate with convolutions 32 are provided in the surface coatingof the conduit 27. Portions of the drill string 17 having a contactingand noncontacting relation with the drum 16 are referred to as major andminor portions of the drill string, respectively. Also provided in thecovering of conduit 27 is a longitudinally extending groove 33functioning in a manner presently explained.

The drill string 17, in its fully assembled position on the drum 16, isreceived in the groove 24 with one end thereof attached to the chamber18 and a conventional air actuated drill tool attached to the other end.

Mounted in the chamber 18 is a compressor, electric motor, and highpressure gas reservoir (none of which are shown). The chamber 18 has afixed relation with respect to and rotates with the drum 16, accordinglyrotary seals are not required between the aforementioned reservoir 18and the conduits 27 and 30.

A slide rod and a slide bar 34 and 36, respectively, have a fixedrelation with respect to the arm 14 and constitute components of theequipment 11. The slide rod 34 carries a roller 37 having a concavesurface, the roller is adapted to slide on the rod 34 as the drillstring 17 is wound and unwound from the drum 16. The bar 34 ispositioned with respect to the drum 16 so that the roller 37 functionsto maintain the drill string 17 firmly in the groove 24 with theconvolutions 32 and 26 in mating relation.

The slide bar 36 carries a block member or torque sensor unit 38 adaptedto slide on the bar 36 as the drill string is wound and unwound from thedrum 16. The member 38 has an aperture provided therein defining aprojection 39 (not shown) adapted to mate with the groove 33.

The motor 19 is of reversible type and functions to drive the drumthrough a conventional device 41 adapted to impart a predeterminedstalling torque to the drum 16 at such time as the drill string 17 isbeing unwound. The motor 19 exerts a torque exceeding the unwindingstalling torque referred to above at such time as the drill string isbeing rewound.

A drill string guide 42 provides a connecting link between the drum 16and a surface casing 47. It consists of an open end rigid tube 43 whichis split and hinged so that it can be placed around the aforementioneddrilling tool and coupled to the surface casing 47 through a flexiblebellows-like coupling 44. Thus it will be apparent that drill stringalignment is provided between the latter and the hole being drilled.

The operation of the equipment 11 follows, at such time as theaforementioned lunar vehicle arrives at its destination the closuremember 12 is opened and the equipment 11 pivotally moved to itsoperating position substantially as shown in FIGURE 1, a support brace46 is secured to fixed structure of the landing vehicle therebymaintaining the arm member 14 in a fixed position. The drum 16 is nowrotated in a direction causing the drill string 17 to unwind from thedrum 16 until the aforementioned air activated drilling tool, secured tothe end of the drill string 17, contacts the lunar surface. Theaforementioned compressor is now activated and a drilling operationinitiated. As soon as a hole is drilled to a predetermined depth thedrilling operation is discontinued, the drilling tool withdrawn and thesurface casing 47 installed in the hole. The drill string guide 42 isalso installed as described above and the drilling continued. Thematerial (core sample removed by the drilling tool is urged upwardly andcollected in the drill guide 42. When the drill guide is full thedrilling operation is discontinued, the drill guide emptied, thematerial labeled for later identification and the operation repeated.

The main or outside conduit 27 of the drill string 17 being constructedof braided wire it will be apparent that the drill string will exert apredetermined force on the drilling tool at such time as the drum 16 isrotated in a direction causing the drill string to unwind. This actionis enhanced by the fact that the longitudinal force developed in thehigh pressure passageway 28 exceeds that produced in the low pressurepassageways 29. Thus the conduit 27 has a tendency to remain straightand rigid, in effect the pressurized gas increases the column strengthof the drill string 17. Inert gas such as nitrogen or the like isrecirculated in the equipment 11 to effect operation of the drillingtool.

While in order to comply with the statute, the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the method and means herein disclosed compriseseveral forms of putting the invention into effect, and the invention istherefore claimed in any of its forms or modifications within thelegitimate and valid scope of the appended claims.

We claim:

1. In drilling equipment the combination comprising: a drum-like memberhaving a spiral groove formed in the cylindrical portion thereof; saidspiral groove having a plurality of spaced depressions definingconvolutions formed therein; a flexible inflatable hose-like memberincluding major portions normally positioned in said groove and having aplurality of spaced projections in the outer surface thereof adapted tomate with the convolutions in the groove and minor portions extendingsubstantially tangentially with respect to the cylindrical portion ofsaid drum; said flexible member defining a compound passageway; saidcompound passageway comprising a plurality of longitudinally extendingpassageways adapted to have pressurized fluid confined therein andfunctioning to render said major and minor portions rigid at such timeas pressurized fluid is confined in said passageways; and meansfunctioning to maintain said major portions in said groove and releasingsaid minor portions from said drum during an inwinding operation of saiddrum.

2. In drilling equipment as set forth in claim 1: in which the outerwall of said hose-like member is constructed of braided wire coveredwith rubber-like material; said compound passageway constituting a highand a low pressure passageway having a concentric relation and in whichthe low pressure passageway surrounds the high pressure passageway; therubber-like material defines a groove extending longitudinallythroughout the length of said hose-like member; a torque sensor unitlocated on a line having a tangential relation with respect to thecylindrical portion of said drum; portions of said torque sensor unitdefining an aperture having an axially extending projection formedtherein; and said hose-like member passing through said aperture withsaid projection received in said groove whereby torque developed in saidminor portions will not be transmitted to said major portions.

3. In drilling equipment as set forth in claim 1: in which the outerwall of said hose-like member is constructed of wire braid covered withrubber-like material; and said plurality of passageways including atleast two passageways, one adapted to carry fluid at a high pressure andthe other fluid at a lower pressure.

4. In drilling equipment as set forth in claim 3: in which said high andlow pressure passageways have a concentric relation with the lowpressure passageway surrounding said high pressure passageway.

5. In drilling equipment as set forth in claim 3: in which therubber-like material defines a groove extending longitudinallythroughout the length of said hose-like member; a torque sensor unitlocated on a line having a tangential relation with respect to thecylindrical portion of said drum; portions of said torque sensor unitdefining an aperture having an axially extending projection formedtherein; and said hose-like member passing through said aperture withsaid projection received in said groove whereby torque developing insaid minor References Cited UNITED STATES PATENTS Smith 137355.23 Krieg137--355.17 Finneburg et al. 242-54 X Palm 137355.19 Wolfe 137355.26 XHannay 137355.2 X Roark 137--355.23 X Kaufman 242-107 Goodliffe et al.137355.26 Powell 137-3552 X portions will not be transmitted to saidmajor portions. 15 SAMUEL SCOTT, Primary Examiner

